Field of the Invention
The present invention relates to a toner suitable for a recording method using electrophotography, electrostatic recording, toner jet system recording, or the like.
Description of the Related Art
A demand for size reduction of the main body of printers and copiers has recently been created with consideration for energy and space saving. The simplification of a fixing apparatus is one of the methods for size reduction of the main body. Film fixing that enables easy simplification of a heat source and an apparatus configuration is a method for simplifying the fixing apparatus. In film fixing, in addition to easy simplification of the heat source and apparatus configuration, thermal conductivity is improved as a result of using a film as a fixing member. Therefore, a first print out time can be shortened. However, since the film is used by pressing against a roller at a relatively high pressure, the film tends to be worn down in a long-term use.
A toner demonstrating satisfactory low-temperature fixability even at a low pressure is needed to resolve this problem. However, a problem arising when the pressure at the fixing nip is reduced and images with a high print percentage are output at a high rate is that the toner tends to peel off from paper (cold offset) because of a small quantity of heat supplied to the toner as well as insufficient toner deformation.
The technique of ensuring appropriate interfacial attachment force or internal aggregation force, which are measured by specific measurement methods, has been suggested as a method for improving the cold offset resistance of toners.
Japanese Patent Application Publication No. 2006-330706 suggests a toner in which an interfacial attachment force (Fr) between the toner and polytetrafluoroethylene, which is measured by a specific measurement method, is at least 1.0 N and not more than 3.5 N and an internal aggregation force (Ft) of the toner, which is likewise measured by a specific measurement method, is at least 10 N and mot more than 18 N. Further, Japanese Patent Application Publication No. 2014-071332 suggests a toner in which an internal aggregation force (F) is at least 5 N and not more than 10 N and an interfacial attachment force (f) is at least 0.5 N and not more than 1 N, the forces being measured using specific measurement methods.